Assembling an M1 Garand Rifle From Parts
Final Assembly

Final Assembly

We are finally ready to assemble our M1 Garand rifle!
We started with a receiver from ODCMP,
a new barrel, and a parts kit
including all the other components including a stock.
We assembled the barrel into the receiver and
reamed the chamber
to its proper dimensions.
Then we parkerized most of
the parts and
restored the wood stock.
Now it's time to put it all together.

This should be pretty straightforward
if you do things in the right order.
Garand gurus will see that I wandered down some blind alleys,
putting things together too soon and then disassembling
and backing up a few steps.

For example, the rear handguard needs to be installed very
early in the overall process.

Only after the rear handguard is installed
can you slide the lower band onto the barrel
and then drive (ideally, press) the pin
into place to hold it there.

Then the forward handguard and its liner and ferrule
slides onto the barrel,
and only then can the gas cylinder assembly
be placed on the muzzle end of the barrel.

Below is the official terminology for the parts:

Below is a half-scale GIF version of an exploded
diagram from a manual.
Click on the image for the full-sized version.

The above exploded diagram shows it completely broken down.
However,
the Field Manuals
are just going to discuss field-stripping and disassembly into
major assemblies.
They certainly aren't going to get into disassembling the
trigger group and bolt!
For good illustrated explanations of how to fully
disassemble and reassemble an M1 Garand, see these
Civiliam Marksmanship Program pages:

Here we go —
all the parts are laid out approximately in their
relative positions.

Sort of a live exploded diagram.

The parts in the rear half are seen here a
little more clearly.

Still missing in this picture but added since —
the butt swivel,
the anchor point for the long screw holding the bottom
of the butt plate in place.

The parts for the front half are
approximately in their relative positions.

Components of the rear sight appear
in their own little exploded diagram.

At left, top to bottom:

Elevating knob and pinionRear sight baseWindage knob

At right, top to bottom:

Rear sight coverAperture

The rear sight components again,
this time as if seen from below.

At left, top to bottom:

Windage knob
Rear sight base
Elevating knob and pinion

At right, top to bottom:

Aperture
Rear sight cover

Here you see a sort of pocket where the rear sight
installs on the receiver.

The rear sight cover snaps into the slots at the
front and rear of this pocket.

A fine star-like pattern of notches
stamped into the "ear" on the left side
(the far side, not visible here) form detents
for the finely space "clicks" of the elevating knob.

Four relatively large and smooth bumps on the outer face
of the "ear" on the right side (dimly visible here)
form detents for four "clicks" per revolution
of the windage knob.

The rear sight base and cover are about to be
installed in place.

The rear sight cover has been snapped into place,
holding the sight base more or less in the correct
position and orientation.

The aperture is being slid onto position.

The windage knob (near side)
and elevating knob and pinion (far side)
are being slid into place.

The windage knob threads into the right sight base.

The elevating pinion screws into that.

The rear sight is finally assembled and ready
to be zeroed!

Turning the windage knob (at right) moves the rear sight
base left to right and the aperture rides with it.

Turning the elevation knob engages the elevation pinion,
and the aperture moves as a rack in,
well, a rack and pinion arrangement.

The front sight attaches to a dovetail on
the forward ring of the gas cylinder.

The gas cylinder itself is made of stainless steel
because of the temperatures involved.

That was good from a metallurgical point of view,
but it causes problems in combat when a rifle includes
a highly reflective part.

Some sort of blacking was typically applied,
either a coating (even carbon from a candle flame)
or a chemical treatment.

The front sight slides onto the dovetail
and the allen screw is tightened.
That compresses the slit body of the sight
onto the dovetail.
The second picture shows that the allen screw has
been tightened.

A gas port in the bottom of the barrel aligns with
a larger hole through the cylinder in the bottom of the
front ring.

The gas cylinder plug will be screwed into the finely
threaded cylinder.
This forces the hot gas to expand to the rear against
the short piston forming the front end of the operating rod.

The gas cylinder assembly slides
onto the barrel.
The non-parkerized region near the muzzle will be
within the front ring of the cylinder.

Three splines at 120° spacing on the barrel
mate with corresponding ridges in the front ring.

It's a very tight fit!

It was too tight on mine at first.
It would take some vigorous smacks with a heavy hammer
against a piece of scrap wood
to drive the gas cylinder onto and off the barrel.

I wrapped the barrel with masking tape immediately in front
of and behind the shiny band seen here.
It's of slightly larger diameter than the rest of the barrel.

I then used fine (#200) metal oxide sandpaper to smooth
this area to the point that the circumferential mill marks
disappeared.

You have to rub along the length of the barrel,
hence the masking tape.
Attempts to run around the barrel just turn this into an
exercise of convering sandpaper to regular paper because
of the slots mating with the splines of the gas cylinder.

The result was that the gas cylinder could be installed and
removed by hand, but it is not at all loose.

The threads on the barrel will engage the gas cylinder lock.

The gas cylinder lock threads onto the barrel,
stopping when
its non-threaded ring is aligned with the gas cylinder.

The gas cylinder plug is then inserted through
the gas cylinder lock
and then threaded into the gas cylinder.

The complete gas cylinder assembly in place!

Of course, as I said above, all this will have to come off.
Everything else must be installed on the barrel first.
The gas cylinder must be the last thing slid on
from the muzzle end.

Duh.

Now it's time to figure out the action....

Left to right below the receiver we see:

The follower.

The bullet guide above the follower arm.

The operating rod catch assembly
above the follower arm pin.

The follower arm passes through the bullet guide.

The follower arm pin will pass through the holes
at the front of the receiver
and through the large holes in both
the follower arm and bullet guide.

Well, it's more complicated than that....

The follower arm pin will also pass through the
operating rod catch assembly.

The action components are in in their
relative positions but not in the receiver.
The follower arm pin has been passed through their
mutually aligned holes.

The two small pins at the rear end of the follower arm
slide into a slot in the bottom face of the follower.
The square bars at the sides of the follower,
one just visible here,
slide into vertical slots in the "legs" of the receiver.

Here are the action components assembled
to each other but not assembled into the receiver.

You can see the holes through the receiver
for the follower arm pin directly above the pin,
and the slots for the follower in the inner faces
of the forward "legs" of the receiver.

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